Field of the Invention
The present invention relates to a measuring cell.
Background of the Invention
The current state of knowledge is as follows.
A variety of measuring cells comprising a measuring cell body and a measuring diaphragm, which is mounted on the measuring cell body, are known from the prior art. When the measuring cell is used, as intended, in at least one measurement section of a top surface of the measuring diaphragm that faces the measurement environment, the measuring diaphragm is in direct contact with the measurement environment.
Pressure measuring cells that are configured to operate in a capacitive mode are often used for this purpose. In such pressure measuring cells the electrodes that are located opposite each other are disposed, on the one hand, on an interior side of the measuring diaphragm and, on the other hand, on a base body; and these electrodes form a measurement capacitance. The forces that act on the measuring diaphragm also cause the distance between these electrodes to change, and this change in distance makes it possible to detect a change in the pressure.
In the prior art such measuring cells are used, for example, in pressure measuring devices. In this case it should be noted that in some applications deposits form over time on the measuring diaphragm. These deposits can often be calcareous accretions or slurries that can form a hard crust in the course of operating the pressure measuring device. This hard crust in turn can lead to significant measuring errors, because they influence the rigidity of the measuring diaphragm or more specifically deform the measuring diaphragm due to the resulting layer tension. Not only metallic top surfaces, such as, for example, stainless steels, but also ceramic top surfaces, such as, for example, aluminum oxide, are often used in pressure measuring technology, where they tend to form highly adherent deposits because of the properties of their top surface. In order to ensure constant quality of the measurement, it is, therefore, necessary, for the user to perform frequent maintenance of such pressure measuring devices, in order to remove the material build-ups. In addition to the drawback that frequent maintenance is necessary, there is also the risk that the measuring diaphragm will be damaged in the course of removing the build-ups.
This is the starting point of the present invention.
The object of the present invention is to provide a pressure measuring cell, which prevents such material build-ups, significantly reduces or at least makes it significantly easier to remove any residual build-ups.
This engineering object is achieved by means of a measuring cell exhibiting the features disclosed herein.